1.2 equations for fields

• solar wind: a stream of high-speed, ionized particles ejected from the Sun, consisting mainly of electrons, protons, and helium nuclei
• cosmic rays: a stream of high-speed, ionized particles ejected from the objects beyond the solar system, consisting mainly of atomic nuclei
• gravitational field strength: the number of newtons per kilogram a test body will experience at a given location from a source mass
• gravitational force: the force exerted on a test body by a gravitation field; calculated by multiplying the mass of the test body by the gravitational field strength
• electric force: the force exerted on a charged test body by an electric field; calculated by multiplying the electric field strength by the charge on the test body
• grounded: connected to the ground; providing a safe conducting path for stray or excess charges; having zero electric potential energy
• electric current: the flow of electric charge from one point to another